1. Field of the Invention
The present invention relates to a photomultiplier tube module.
2. Related Background Art
Conventionally, a photomultiplier tube module formed by incorporating a photomultiplier tube in a housing is known as a unit capable of detecting weak light. The photomultiplier tube module described in Patent Document 1 (Japanese Patent Application Laid-Open No. 2004-125626) applies a high voltage to a photomultiplier tube and processes an output signal from the photomultiplier tube by a signal processor. The photomultiplier tube modules described in Patent Document 2 (Japanese Patent Application Laid-Open No. 2005-30972) and Patent Document 3 (Japanese Patent Application Laid-Open No. 2003-130726) control incidence of light by attaching a shutter on the side of a light incident surface of a photomultiplier tube. These photomultiplier tube modules, despite being small-sized, function as excellent detectors that enable detection of weak light.
Particularly, for the photomultiplier tube module described in Patent Document 2, an amplifier board that amplifies an output signal from the photomultiplier tube is incorporated in a housing, and the amplified output signal can be outputted to the outside. The amplifier board is arranged parallel to a tube axis of the photomultiplier tube.